1. Field of the Invention
The present invention relates generally to fluid (e.g., air) filters, and more particularly, to bag fluid filters that can be utilized with a baghouse environment.
2. Discussion of the Prior Art
Fluid filters are known and used in many different applications, including baghouses. Each baghouse may be provided with one or more fluid filters for filtering dirty fluid (e.g., air) in various functions such as fuel-based power generation, chemical/cement/mineral processing, incineration, etc. Current technology filters include filter cartridges, which have filtration media and associated structures provided and replaced as a unit, and replaceable “bag” media which envelope cages that need not be replaced as often as the bag-type media.
Focusing upon bag-type media, the underlying cages are generally elongate and have a cylindrical shape. The filtration bag generally has a shape that corresponds to the shape of the cage enveloped by the filtration bag. It is to be appreciated that replacement of the filter media onto a cage involves an insertion movement of the cage into the bag, with the bag being a receptacle for the cage. The dimensions of the cage relative to the bag are such that the cage can be inserted into the filtration bag without binding of the bag and also such that the filtration bag is not damaged (e.g., torn, punctured, or otherwise stressed). As such, there is some amount of space or looseness of the filtration bag relative to the cage. In other words, the filtration bag is not form-fitting to the cage to allow the insertion to occur.
In view of the looseness of the bag, it is possible that some bag movement relative to the cage can occur during operation. For example, during filtration flow, the filtration bag may be forced against the cage because of a flow. However, during a pulse cleaning cycle, the filtration bag may move away from the cage. Movement of the filtration bag may cause stresses, wear or the like. It may be beneficial to reduce or eliminate some filtration bag movement to help avoid stress, wear, etc.
Such stress, wear, etc. can be more of an issue for certain types of bags. For example, some types of bags include glass fibers. One specific example type of glass-containing bags are bags that include woven glass fibers. Often the woven glass fibers may include fibers extending vertically and fibers extending horizontally. The glass fibers can and do break if bent/flexed beyond a tolerance level during bag movement. The above-mentioned bag movement can thus cause breakage of the glass fibers. Such fiber breakage may be especially prevalent at folds, pleats, creases or the like. Fibers that extend transversely to such folds, pleats, creases or the like may have a heightened amount of bending/flexing at the folds, pleats, creases or the like and thus may have a heightened propensity to break. As such, the bag may develop damage or wear “patterns” at the folds, pleats, creases or the like. For very long bags, the folds, pleats, creases tend to extend along the elongation of the bag. So, if the bag is vertically oriented, the folds, pleats, creases or the like would similarly be vertically extending. Therefore, the damage or wear “patterns” may extend along the relatively long extent of the bag and thus can become significant.
Accordingly, it may be beneficial to reduce or eliminate some filtration bag movement to help avoid stress, wear, etc.